The synthesis of polyacetylene compounds as described in European patent 0032622 by the Glazer and Chadiot-Chadohiewicz method (Chemistry of Acetylenes by A. G. Viehe, pages 598-641) is achieved by terminal coupling of acetylenes in the presence of an alcohol diluent, i.e. methanol. Up to 600 mole % copper ion is used to effect synthesis and the crude product recovered contains from 30 to 80% polyacetylene and up to 30% copper impurity in the form of copper ion and complexed acetylides as well as unreacted amine impurities. Conventionally, for purification, the product mixture is acidified and extracted with ethyl acetate solvent, which operation requires caution due to the high flammability of the extractant. Since the liquid phases formed during the extraction with ethyl acetate solvent are not clearly defined, a significant amount of the polyacetylene is lost in the aqueous phase. Further it has been found that the copper complexed acetylene impurities, which are soluble in the methanol diluent employed in the above processes, are also extracted in the ethyl acetate phase and that removal of the ethyl acetate from product leaves behind polyacetylene product contaminated with copper impurity.
Accordingly, it is an object of this invention to overcome the above deficiencies by an economical and commercially feasible process.
Another object of this invention is to provide a polyacetylene product having greatly reduced copper acetylide contamination.
Still another object is to reduce the copper contamination of diacetylene by at least two-fold.
These and other objects of the invention will become apparent from the following description and disclosure.